GB182898A - Improvements in and relating to dynamo electric machines - Google Patents

Abstract

182,898. Morgan, S. B. April 9, 1921. Dynamos and motors, cooling; field magnets, cooling; pole-pieces and cores.-In a dynamoelectric machine having cast pole-pieces upon which field coils are wound and in which radial passages are formed, a fan is mounted upon the armature spindle and draws air into the casing and forces it through the passages in the polepieces to cool them. In the construction shown in Fig. 1 the fan j mounted in the end plate cover o draws in air through the radial apertures m. Part of the air passes out through the peripheral apertures n and part through the apertures r, q in the other end plate p after passing through the machine, while the remainder passes out through the radial apertures in the pole-pieces. In a modification the air which passes out through the apertures n is led by passages w, Fig. 5 to the outer ends of the apertures d in the upper pair of pole-pieces, so that air is forced into the casing through the upper pair of pole-pieces. In place of the apertures m, suitable pipe inlets may be provided for supplying fresh air to the casing. In this case the peripheral apertures may be dispensed with so that the sole outlets for the air are the apertures in the pole-pieces. The poleshoes c are formed as detachable sleeve members retained in position by fixing-studs. The polepieces may be cast so that the cross-section of each is a rhomboidal parallelogram as indicated at b<1>.